Tunable imaging members and process for making

Abstract

A method for forming an electrostatographic photoreceptor includes the steps of selecting a desired sensitivity range and a desired light intensity for a photoreceptor and forming the photoreceptor having the desired sensitivity range and desired light intensity. The photoreceptor includes a supporting substrate and a photogenerating layer including a charge generating material, formed by coating the photogenerating layer on the supporting substrate. The charge generating material is formed by a process including dispersion milling a photogenerating material for a selected period of time, selected in accordance with the desired sensitivity range and the desired light intensity, to adjust the desired sensitivity range and desired light intensity of the photoreceptor.

Claims

1. A method for forming an electrostatographic photoreceptor, comprising:

(a) selecting a desired sensitivity range and a desired light intensity for a photoreceptor; and

(b) forming said photoreceptor having said desired sensitivity range and said desired light intensity comprising a supporting substrate and a photogenerating layer comprising a charge generating material by coating said photogenerating layer on said supporting substrate;

wherein said charge generating material is formed by a process comprising dispersion milling a photogenerating material for a selected period of time, selected in accordance with said desired sensitivity range and said desired light intensity, to adjust said desired sensitivity range and said desired light intensity of said photoreceptor.

2. The method of claim 1, wherein said photogenerating layer comprises a separate charge generating layer and a separate charge transport layer, and said charge generating material is contained in said charge generating layer.

3. The method of claim 1, wherein said photoreceptor has a sensitivity in a range of from about 40 to about 90 V-cm.sup.2 /erg at a V.sub.ddp of 600 V.

4. The method of claim 1, wherein said photoreceptor has a light intensity in a range of from about 7 to about 25 erg/cm.sup.2 at 100 V.

5. The method of claim 2, wherein said photoreceptor forming step comprises providing said supporting substrate, applying a blocking layer to said supporting substrate, applying said charge generating layer over said blocking layer, and applying said charge transport layer over said charge generating layer.

6. The method of claim 1, wherein particles of said charge generating material have an average particle size of from about 0.03 to about 0.20.mu.m.

7. The method of claim 1, wherein particles of said charge generating material have an average particle size of from about 0.05 to about0.15.mu.m.

8. The method of claim 1, wherein said charge generating material is selected from the group consisting of amorphous selenium, trigonal selenium, selenium alloys, metal-free phthalocyanine pigments, metal phthalocyanines, dibromoanthanthrone, squarylium, quinacridones, dibromo anthanthrone pigments, substituted 2,4-diamino-triazines, and polynuclear aromatic quinones.

9. The method of claim 1, wherein said photogenerating material and said charge generating material are benzimidazole perylene.

10. The method of claim 9, wherein said benzimidazole perylene is selected from the group consisting of bisbenzimidazo(2,1-a:1',2'-b')anthra(2,1,9-def:6,5,10-d'e'f')diisoquinolin e-6,11-dione and bisbenzimidazo(2,1-a:2',1'-a')anthra(2,1,9-def:6,5,10-d'e'f')diisoquinolin e-10,21-dione.

11. The method of claim 1, wherein said period of time is from about 2 to about 100 hours.

12. The method of claim 1, wherein said dispersion milling is conducted in a milling apparatus selected from the group consisting of a jar mill, a ball mill, an attritor, a sand mill, a paint shaker, a dyno mill, and a drum tumbler, said milling apparatus including a grinding media selected from the group consisting of round, spherical or cylindrical grinding beads of steel balls, ceramic cylinders, glass balls, round agates and stones.

13. The method of claim 1, wherein said dispersion milling grinds said photogenerating material to a smaller size to form said charge generating material.

14. A method for tuning sensitivity and light intensity of an electrostatographic photoreceptor, comprising:

(a) selecting a desired sensitivity range and a desired light intensity for a photoreceptor;

(b) dispersion milling a photogenerating material for a period of time sufficient to provide said photogenerating material with said desired sensitivity range and said desired light intensity; and

(c) forming said photoreceptor having said desired sensitivity range and said desired light intensity by a process comprising coating a photogenerating layer comprising a charge generating material onto a supporting substrate.

15. An electrostatographic photoreceptor having a specific desired sensitivity range and specific desired light intensity, produced by the process of claim 1.

16. An electrostatographic photoreceptor having a specifically-tuned sensitivity range and specifically-tuned light intensity, produced by the process of claim 14.

17. The method of claim 1, wherein said charge generating material is selected from the group consisting of amorphous selenium, trigonal selenium, selenium alloys, metal-free phthalocyanine pigments, metal phthalocyanines, dibromoanthanthrone, squarylium, dibromo anthanthrone pigments, and substituted 2,4-diamino-triazines.

18. The method of claim 1, wherein said dispersion milling is conducted in a milling apparatus and consists essentially of milling said photogenerating material with a grinding media and optionally a solvent.